export default {
  namespaced: true,
  state: () => ({
    // 购物车的数组，用来存储购物车中每个商品的信息对象
    // 每个商品的信息对象，都包含如下 6 个属性：
    // { goods_id, goods_name, goods_price, goods_count, goods_small_logo, goods_state }
    cart: JSON.parse(uni.getStorageSync('cart') || '[]'),
  }),
  mutations: {
    addToCart(state, goods) {
      // 如果购物车中已经有了该商品,则商品数量加1,否则将该商品加入购物车
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      if (!findResult) {
        state.cart.push(goods)
      } else {
        findResult.goods_count++
      }
      // 通过 commit 方法，调用 m_cart 命名空间下的 saveToStorage 方法
      this.commit('m_cart/saveToStorage')
    },
    saveToStorage(state) {
      uni.setStorageSync('cart', JSON.stringify(state.cart))
    },
    // 更新radio勾选状态
    updateGoodsState(state, goods) {
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      if (findResult) {
        findResult.goods_state = goods.goods_state
      }
      // 持久化存储到本地
      this.commit('m_cart/saveToStorage')
    },
    // 更新商品购买数量
    updateGoodsCount(state, goods) {
      const findResult = state.cart.find(x => x.goods_id === goods.goods_id)
      if (findResult) {
        findResult.goods_count = goods.goods_count
      }
      // 持久化存储到本地
      this.commit('m_cart/saveToStorage')
    },
    // 删除购物车商品
    removeGoodsById(state, goods_id) {
      state.cart = state.cart.filter(x => x.goods_id !== goods_id)
      // 持久化存储到本地
      this.commit('m_cart/saveToStorage')
    },
    // 更新所有商品的勾选状态
    updateAllGoodsState(state, newState) {
      state.cart.forEach(x => x.goods_state = newState)
      // 持久化存储到本地
      this.commit('m_cart/saveToStorage')
    }
  },
  getters: {
    // 统计购物车中商品总数量
    total(state) {
      return state.cart.reduce((sum, cur) => {
        return sum += cur.goods_count
      }, 0)
    },
    //统计已勾选商品数量
    checkedGoodsCount(state) {
      return state.cart.filter(x => x.goods_state).reduce((sum, cur) => sum += cur.goods_count, 0)
    },
    // 统计已勾选商品总价格
    checkedGoodsTotalPrice(state) {
      return state.cart.filter(x => x.goods_state).reduce((sum, cur) => sum += cur.goods_count * cur.goods_price, 0)
        .toFixed(2)
    }
  }
}